[6.05] The Fueling of Active Nuclei: A NICMOS Snapshot Survey of Seyfert and Normal Galaxies

Galactic bars are frequently invoked as a candidate for
facilitating the transfer of mass from the interstellar
medium of active galaxies to their central engines. However,
the incidence of bars in these active galaxies is no higher
than that in quiescent spiral galaxies based on recent
ground-based studies of Seyferts. Furthermore, numerical
simulations indicate that gas inflow generated by a
large-scale stellar bar does not extend down to the scales
required to feed the central engine. However, simulations
also indicate that a series of nested gaseous bars may
form in some cases, driving inflow of gas to the scales
where the central blackhole dominates the potential.

We present initial results of a HST NICMOS snapshot survey
of a sample of Seyfert and quiescent galaxies which we use
to test this "bars-within-bars" model for fueling the
nucleus. Only the resolution of NICMOS can reach the size
scales needed (10--50 pc) to test the model. We will combine
the NICMOS images with existing data to search for
small-scale stellar bars and the dust associated with
gaseous bars and to search for differences between the
active and normal galaxies that might explain the
differences in observed activity.